The present invention relates to an outer metallic stairway, particularly made of aluminium, for multistage buildings or buildings of a rather important height, said stairway being generally intended to be used for allowing the occupants of a multistage building to evacuate this one and persons to go out and/or to go in by an outside means, and being designed in such a manner as to be essentially self-supporting so that it may be provided for a multistage building to be erected; the stairway is also particularly useful in the case of a multistage building already existing which is to be provided with an evacuation facility or an outside outlet, i.e. it may be adapted to a multistage building formerly constructed. The stairway in accordance with the present invention is only to be attached against a main wall, for example the front wall of the building without being hooked to the wall of the building, i.e. without being carried by said wall.
Outer stairways of rather numerous various types have a course already been proposed. The known stairways are either made of elements that are independant of one another from story to story and are carried by the front wall of the building except the lowest one or they are made of elements that are connected with one another, the whole or nearly the whole of the stairway being supported by the front wall of the building at different points of the height of the stairway and as a rule at least at one point per story so that an important work is to be carried out for fixing the stairway to the front wall of the building. There are also stairways that may be regarded as self-supporting and that are real metallic columns with the stairway rising inside.